jw4 Smokey's JW4 Formula Four Rebuild Thread

[Mark (smokey mow)]

34 minutes ago, MMB said:

Hi Smokey

Been a while since I checked in...looks fantastic!

Here are a few pics of the firewall I made for my JW4 when I had it. Very simple and rests on the rails and still lets the air flow from the NACA duct under the seat to the engine bay.

All the best

MMB

Hi Bob, its been a while, I hope you're keeping well.

the firewall on your car was a very elegent solution which I like a lot, thank you for the photos.

for our UK racing regulations the firewall needs to provide a complete seal between the driver and engine compartment to create a barrier against fuel spillage or fire.  On this car the body is from the JW4 Mk2 so lacks the air ducts that were fitted to Mk3 body on your JW4 and my blue car.  The rear engine cover on the mk2 is much lower than the Mk3 so the cylinder head of the engine sits in the airstream for cooling rather than enclosed within the bodywork.

my hope is that a simple flat aluminium closing plate will be sufficent behind the seats cut to match the curve of the body, but I may need to get creative with carboard first to get the shape right.

[Mark (smokey mow)]

A few more small jobs completed today....

The first job was the manual control for the mechanical fuel pump.  Like most F4 cars of the period the JW4 ran a mechancial fuel pump which was driven off a cam on the back axle.  These as you'd expect would work fine when the car was moving but when the car is stationary and therefore the axle not turning there needed to be another way of getting the fuel to the engine. The Pathe videos showed the mechanics frantically priming the pump by hand but as I studied the photos and videos a bit closer many drivers also employed another method so the pump could be controlled from the drivers seat.

the solution they used was very simple which was a bicycle brake leaver mounted below the dash and cable linked to the pump.

 

[Mark (smokey mow)]

The next job was to make the driveshafts. The JW4's used shafts and hubs of Johnny Walker's own design, however the Carburol Special ran an uprated design for hillclimbing with the uprights machined for BMC Mini stub axles and shafts. Unfortunately the shafts were missing from the boxes of spares I'd acquired so I would need to make some new ones. 

Starting with a par of standard mini driveshafts the length needed was measured and then cut to length.

 

I happened to have a pair of driveshaft spiders that I'd had claser cut for the first car but the centre hole was too small so I opened this up to the required diameter on the lathe.

 

Mounted back on the car to check the length and now just the welding to complete.

[Mark (smokey mow)]

The final job of the day as the light faded was to fit the battery isolator switch.

I also made a short teather for the key using a length of brake cable and a coupke of crimp terminals so it wouldn't go missing.

 

[pistonbroke]

Ingenious 

[Alan Cutler (Adge) - Dorset AO]

Like the hand priming set up, very clever. I like simple!

[Mark (smokey mow)]

Driveshafts welded, painted and fitted today.

As I'm trying to avoid using plastic cable ties anywhere on the car I fitted metal clips to secure the driveshaft gators. 

[KugaWestie]

Nice work as always 

[Mark (smokey mow)]

48 minutes ago, KugaWestie said:

Nice work as always 

Cheers Gary, the list of jobs to finish is quickly getting shorter.

[Alan Cutler (Adge) - Dorset AO]

Really enjoying your great work Mark. Any thoughts on timescale to get them Up and running? Not wishing to pressurise you.

[Mark (smokey mow)]

27 minutes ago, AdgeC said:

Really enjoying your great work Mark. Any thoughts on timescale to get them Up and running? Not wishing to pressurise you.

Thanks. This ones not going to be a runner which is decision I thought long and hard about for quite a while before the build started. It was always my intention that this car would be offered for sale once completed and i wanted to build it in a way that gave as much choice as possible to the prospective buyer as to how they'd use it.  For that reason, the engine I'm fitting is a dummy (empty set of cases) which is fine for display and easy to swap out for either another triumph twin or an alternative engine as I have drawings of the engine crades to suit most of the period racing motorcycle engines.

The plan at the moment is to have this built completed before the summer, after which I really want to get the last few jobs on the first (blue) car finished, which involves stripping it back down again so I can paint the chassis, then it's the final reassembly.  The Villiers Starmaker in the blue car is a running engine so this car will be raced at some time in the future.  Depending on how the build of the white car goes I could have the blue one finished by the winter of this year.

[Mark (smokey mow)]

Over the years I've been writing this build thread I've spoken to a fair few people about Formula IV in that time and wherever possible I've documented it in this thread.  There has been the very rare occasion though that for various reasons I've haven't published certain meetings or details.

One such meeting took place in May 2017.  I'd been following up on an old lead trying to find the very last of Johnny Walker's cars, a collaboration with Frank Costin which was to be the Costin Walker.  My interest was sparked in this particular car as it was reputably the strongest space frame chassis ever to be produced and Frank Costin later went on to patented the design.  Unfortunately as the car was very much in prototype form when it was displayed for the first time at the 1969 Racing Car Show the cockpit and the unique chassis was hidden from photographers view. The other reason for my wanting to find the owner was that in amongst all the drawings I had acquired for the JW4's I had a small number for the Costin which I felt should be passed to the owner.  

 

I had scant information to guide me in my search and the only lead was an old magazine clipping from a classic car magazine in 1991 giving a possible name for the then owner but as luck would have it my googling and emails paid off and they still had it.

 

The car had been bought by him back in 1977 and was by now in a condition where it was stripped down for a full rebuild.  The parts were all there but tired and deteriorated given their age but it was obvious this was the car and the story checked out. 

As I'd published on this thread before the design and Development of the Costin Walker was somewhat ad-hoc with Costin only working on the project when Walker had raised sufficient funds to pay him for the next stage of work. Frustrated with progress Frank Costin eventually left the project and Walker handed over the development to Tony Hilder of Piper cars with the car being renamed the Type AH after Hilders initials. Hilder's brief was to sort the handling of the car which required some modifications to the suspension geometry. The drawings I had were of Hilder's modifications and charted the bump plots of the suspension and the revised rear upright design which matched exactly those which are now with the car.

When I saw the car 2 years ago work had restarted on the rebuild, the chassis had been painted and some of the aluminium parts had been remade. It was looking likely that the car would be back together soon so rather than spoil the surprise it was decided to wait for the car to be completed again for that big reveal after all the years of hiding.

 

So a few of you are probably now thinking that this is it and the Costin Walker is now complete again but unfortunately it wasn't quite to be.  Progress stalled and a change of plans for the owner meant that the for the first time in 42 years they were now thinking of selling up.

[Mark (smokey mow)]

The news of the sale came as quite a surprise to me and even more so that I was being offered first refusal on it. This was a car which I felt would be well beyond my reach and a project which I could only hope to work on but here was that opportunity.

Well you can guess the rest (or if you're on Facebook then you might already have read). Yes this is the story of how I came to become the new owner of Frank Costin's Auto XVIII.

 

[Alan Cutler (Adge) - Dorset AO]

Well done Mark, great to see you're taking on another challenge. Guess boredom isn't a feature of your life! Looking forward to updates on progress. Keep up the good work.

[SootySport]

What!  another one Mark?

I really admire your dedication to restoring older race cars but please get some driving time in this year and meet up with her Essex buddies.

We miss you.